Pneumatic circuit

ABSTRACT

A pneumatic circuit and other components are provided for the operation of a medical device. The pneumatic circuit provides controlled pressurized air to a medical device for use during a medical procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Ser. No. 60/374,952 filedApr. 23, 2002.

BACKGROUND OF THE INVENTION

The present invention relates to a pneumatic circuit, and particularlyto a pneumatic circuit for use in the operation of an at least partiallyair-powered tool. More particularly, the present invention relates to apneumatic circuit useful in the pneumatic operation of a medical device.

SUMMARY OF THE INVENTION

The present invention relates to one or more of the following features,elements or combinations thereof. A pneumatic control system is providedfor use with a medical device, illustratively a suction biopsy device.The suction biopsy device has a cannula for insertion into a body to apoint adjacent to a mass to be examined, and a rotating cutter device ishoused within. The cannula has an orifice, and a pneumatic cylinder iscoupled to the cutter for moving the cutter relative to the orifice.

A rinse or illustratively saline solution is provided for assisting inthe removal of the mass to be examined. A suction is provided forassisting in the removal of the mass to be examined. The control systemhas an absence of electrical circuitry configured to control theoperation of the suction biopsy device. Electrical power isillustratively provided only for the compressor and the vacuum.

The cannula defines an axis and the cutter is illustratively alignedcoaxially with the cannula for rotation about the axis. A pneumaticmotor actuates the rotational movement of the cutter. The pneumaticcylinder causes the cutter to move axially relative to the cannula.

A method of removing a tissue mass from a body is also provided. Themethod comprises the steps of inserting a hollow cannula having anaperture into the body such that the aperture is positioned adjacent tothe tissue mass. Suction is provided to the cannula such that a portionof the tissue mass is pulled inside the cannula through the aperture.The cutter is pneumatically caused to move relative to the aperture sothat the cutter cuts the portion of tissue mass from the remainder ofthe tissue mass. The cut portion of tissue mass is then transportedthrough the cannula with the provided suction. The pneumatic movement ofthe cutter is controlled by a pneumatic circuit comprising a pressuresensor.

The control system drives a cutter blade connected to the biopsy device.The cutter blade moves from a recessed position to an extended position.The control system cycles the cutter between the recessed position andthe extended position at a predetermined cycle rate, responding to usercommands when determining whether to continue to cycle.

A pneumatically driven motor rotates the cutter. A pneumatically drivenpiston moves the cutter between the recessed position and the extendedposition. Pressurized gas is delivered to the pneumatic motor, and asaline supply is delivered to the cannula.

Suction assists in removing the mass from the body during a surgicalprocedure. The control system is configured to run continually but havecyclical elements responding to the continual operation.

Additional features of the disclosure will become apparent to thoseskilled in the art upon consideration of the following detaileddescription of preferred embodiments exemplifying the best mode ofcarrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a top perspective partial view of a Breast Biopsy Systemhaving a hand wand, the Biopsy System including a pneumatic circuitinternally, the circuit configured to operate the Biopsy System and handwand;

FIG. 2 is a perspective view of the system shown in FIG. 1;

FIG. 3A is a view of the cannula of the hand wand inserted into apatient's breast adjacent a tissue mass, the cannula having an aperturepositioned adjacent the mass;

FIG. 3B is a view similar to that of FIG. 3A, showing a cylindricalcutter that has moved inside the cannula, thereby cutting away a portionof the tissue mass;

FIG. 4 is a view of an air compressor shown upside down with tie-downrails and springs attached;

FIG. 5 is a view of the compressor of FIG. 4, showing the compressorright side up with additional fittings;

FIG. 6 is a view of a vacuum pump showing the tie-down rail and springs;

FIG. 7 is a view of the compressor of FIGS. 4-5 and the vacuum pump ofFIG. 6 both installed in a console;

FIG. 8 is a view of a console mounting panel showing manifoldsubassemblies, a filter subassembly, and a terminal block subassemblymounted on the mounting panel;

FIG. 9 is a view of the console showing the mounting panel mounted inthe console, and showing the cavity in the lower portion which housesthe compressor and vacuum;

FIG. 10 is a view from the top of the console of FIG. 8;

FIG. 11 is a view from the front of the open console similar to that ofFIG. 9, showing the compressor and vacuum pump mounted in the lowerportion of the console and showing other components of the pneumaticcircuit mounted in the upper portion of the console;

FIGS. 12A-B are views of two embodiments of a water evaporationsubassembly;

FIGS. 13A-B show, respectively, the foot switch prior to attachment oftubing, and the foot switch partially assembled after the attachment oftubing;

FIG. 14 is a view of the terminal block subassembly;

FIGS. 15A-B are perspective views of the two manifolds configured toroute the pneumatic tubing within the console;

FIGS. 16A-B are schematic representations of the pneumatic circuitelements;

FIG. 17 is a schematic representation of an evaporation valve portion ofthe pneumatic circuit;

FIG. 18 is another schematic representation of a portion of thepneumatic circuit;

FIGS. 19A-D show specification drawings for the console;

FIG. 20A shows the configuration of the control panel;

FIG. 20B shows the configuration of the manifolds with relation to thefilters and connection points;

FIGS. 21A-D show diagrammatic representations of the manifolds depictingthe ports and internal passageways associated with the manifolds;

FIG. 22A shows a top view of a pinch valve configured to control theflow of saline;

FIG. 22B is a front elevation view of the pinch valve shown in FIG. 22A,showing the tube positioned in the pinch valve, and showing the movementof the plunger between a flow position and a non-flow position;

FIGS. 23A-D show specification drawings for the gasket;

FIGS. 24A-B show a top view and a front elevation view, respectively, ofa canister bracket;

FIGS. 25A-D show front and side views of a pair of hose wrap pins;

FIGS. 26A-B show a foot switch holder;

FIG. 27 shows a valve bracket;

FIGS. 28A-B show an embodiment of tie-down rails;

FIGS. 29-33 show the test equipment used in testing certain elements inthe pneumatic circuit in various stages of the test; and

FIGS. 34A-C show parts listings of the various parts used in theconstruction of the Breast Biopsy System.

DETAILED DESCRIPTION OF THE DRAWINGS

One embodiment of the present disclosure is shown in FIGS. 1 and 2 inthe form of a Breast Biopsy System 2 having a hand wand 4. Biopsy System2 illustratively includes a console 6 having an access door 8 and acontrol panel 9 positioned toward the top of the console 6. BiopsySystem 2 includes an internal pneumatic circuit 10 (shown in FIGS. 8-12and schematically in FIGS. 16-18) that is configured to operate amedical device 70, illustratively hand wand 4, as will be discussed inmore detail below. It should be understood that as used herein, medicaldevice 70 can be any medical device that is powered at least in part bypneumatic pressure. The illustrative medical device 70 comprises a handwand 4, and such terms are used interchangeably throughout.

Biopsy System 2, and particularly hand wand 4, illustratively functionin the following manner. A patient having a mass 142 to be removedreceives a local anesthetic and the mass is identified and located inthe patient. Location methods may include ultrasound, magnetic resonanceimaging (MRI), X-Ray, or any other method known in the medical industry.As can be seen in FIGS. 1 and 3A-B, hand wand 4 illustratively includesa hollowed needle or cannula 130 extending therefrom, the cannula 130having a sharp distal end 136 for facilitating piercing into thepatient's body, and the cannula 130 further having a cutter 134positioned therein for rotational and axial movement relative to thecannula 130. Cutter 134 is illustratively a cylindrical blade, but otherconfigurations are within the scope of the disclosure. Distal end 136 isillustratively a frusto-conical stainless steel tip press-fitted on theend of cannula 130, the tip having a plastic cutting board (not shown)housed within for receiving cutter 134 when cutter 134 is at its fullstroke position.

An aperture 132 is illustratively formed in the cylindrical wall ofcannula 130 at its distal end. During operation, as shown in FIGS. 3A-B,a physician inserts cannula 130 into the patient (i.e. the cannula isinserted into a woman's breast) such that aperture 132 is positionedproximal to a mass 142 to be removed. While the cannula is beinginserted into the patient's body, the cylindrical cutter 134 ispositioned inside cannula 130 such that cutter 134 substantially closesoff aperture 132. Pneumatic circuit 10 directs compressed air topneumatic cylinder 26 in order to position cutter 134 at its full strokeposition.

After cannula 130 is in position in the patient's body, pneumaticcircuit 10 directs the retracting and advancing movement of cutter 134relative to the cannula 130 in response to signals from a foot switch16, a remote push button 18, or a panel push button 18A (see FIG. 16B)operated by a medical technician or surgeon. Once the operator signalsfor the cutting to begin, pneumatic circuit 10 directs vacuum pressureto hand wand 4, and pneumatic circuit releases the compressed air frompneumatic cylinder 26 (which is illustratively housed in hand wand 4).Once compressed air is released from pneumatic cylinder 26, a springurges the plunger in pneumatic cylinder 26 toward the retractedposition, thereby causing cutter 134 to move to the retracted position,consequently opening aperture 132. Vacuum pressure is also applied bypneumatic circuit 10 to the inside of cannula 130, causing a portion ofthe mass 142 to be drawn inside cannula 130. While the portion of themass 142 is drawn inside cannula 130, pneumatic circuit 10 sendscompressed air to cylinder 26, thereby moving cutter 134 relative toaperture 132 toward the extended, full-stroke position. At substantiallythe same time, pneumatic circuit 10 further directs compressed airtoward a pneumatic motor 138 housed in hand wand 4. Pneumatic motor 138is coupled to cutter 134 and causes cutter 134 to rotate about its axisinside cannula 130. As a result of the rotational and axial movement ofcannula 130, cutter 134 cuts the portion of the mass 142 that extendsinside the cannula 130 as cutter moves toward distal end 136 of cannula130.

Once cutter 134 has completed such a cycle and has returned to theposition wherein aperture 132 is closed, pneumatic circuit 10 confirmswhether further cutting will be necessary. Such confirmation is receivedfrom foot switch 16 or remote push button 18/panel push button 18A,described further herein. In the illustrated embodiment, a short pauseof approximately a half second prior to confirmation allows sufficienttime for an operator to determine whether additional cutting will benecessary.

If additional cutting is not deemed to be required and the mass 142 isconsidered removed, the operator removes cannula 130 from the patient'sbody. If instead confirmation is made that additional cutting isrequired, pneumatic cylinder 26 causes cutter 134 to again move to theretracted position, thereby opening the aperture 132, and saline isdirected through the hand wand 4 and between cannula 130 and cutter 134.Saline passing over the cutting end 140 of cutter 134 is suctioned intothe central portion of the cannula 130 with urging from theaforementioned applied vacuum pressure. Suctioning saline through thecentral portion of cannula 130 serves to flush the cut portion of themass through the cannula toward a waste canister 28, described furtherherein. Additionally, the saline serves as a lubricant between thecannula 130 and the cutter 134. In the illustrative embodiment,pneumatic motor 138 is not actuated while cutter 134 is moved toward theretracted position, therefore cutter 134 does not rotate relative tocannula 130 during this retraction phase. Such operation is desirable sothat tissue does not wrap around cutter 134 as cutter 134 retracts.

Pneumatic circuit 10 directs the continuous above-described cycling ofcutter 134 as long as foot switch 16 or remote push button 18 or panelpush button 18A is depressed. Illustratively, ultrasound, magneticresonance imaging (MRI), or other mass-locating methods known in the artmay be used during the procedure in order to monitor the progress of theremoval of the mass 142. It is advantageous that Breast Biopsy System 2,in one embodiment, can be used in conjunction with an MRI device becauseof the majority of its components being pneumatic and non-magnetic.

The components comprising pneumatic circuit 10, and their associatedfunctions in the control of hand wand 4, are described below. FIGS. 4and 5 show views of an air compressor 11 having tie-down rails 13 andsprings 15 attached thereto. Fittings 17 are coupled to the top of aircompressor 11 as shown in FIG. 5, and air compressor 11 isillustratively mounted in the rear of the console 6 as shown in FIG. 7.

A vacuum pump 19 is shown in FIG. 6, the vacuum pump having a tie-downrail 21 and springs 23. FIG. 7 shows the relative placement of vacuumpump 19 and air compressor 11 in the lower portion of console 6.Soundproofing material 37 is also placed in the proximity of vacuum pump19 and air compressor 11 in order to muffle the sound of air compressor11 and vacuum pump 19 during operation.

FIG. 8 is a view of a console mounting panel 25 showing manifoldsubassemblies 27, 29, an evaporation subassembly 31, and a terminalblock subassembly 33 mounted on the mounting panel 25. FIGS. 9 and 10show the console mounting panel 25 mounted in the console 6. Compressor11 and vacuum pump 19 are not installed in the illustrative FIGS. 9 and10.

Console 6 is shown in FIG. 11 to have compressor 11 and vacuum pump 19mounted in the console 6 while other components of pneumatic circuit 10including console mounting panel 25 are mounted in the upper portion ofconsole 6. Shelf 35 is mounted to divide console mounting panel 25 fromcompressor 11 and vacuum pump 19. As noted above, soundproofing material37 is positioned to surround compressor 11 and vacuum pump 19.

FIG. 12A shows water evaporation subassembly 31 prior to installation inpneumatic circuit 10. Water evaporation subassembly 31 includes a filter41, relief regulator 43, and gas-permeable absorber 45. Filter 41 isconfigured to direct condensation toward gas-permeable absorber 45,which in turn dissipates the condensation into the atmosphere. Theschematic representation of water evaporation subassembly 31 can be seenin FIG. 17.

FIG. 12B is an alternative embodiment 31′ of the water evaporationsubassembly 31 of FIG. 12A. In alternative embodiment 31′, conduits andfitting of subassembly 31 are replaced with manifolds 34, 36. Manifolds34, 36 act as conduits and as fitting receivers for components such asfilter 41, relief regulator 43, and gas-permeable absorber 45.

FIGS. 13A and 13B show the assembly of foot switch 16 prior to and afterthe attachment of tubing. FIG. 14 is a view of the terminal blocksubassembly 33 prior to installation on the console mounting panel 25,shown in FIG. 8. The terminal block subassembly 33 functions todistribute electrical power to the compressor 11, vacuum pump 19, anddump valves.

Custom designed manifolds 47, 49 can be seen in perspective view inFIGS. 15A-B. Manifolds 47, 49 are configured to route the pneumatictubing (not shown in FIGS. 15A-B, but viewable in FIG. 8) within theconsole. Schematics for manifolds 47, 49 can be seen in FIGS. 20B and21A-D.

FIGS. 16A-B illustrate the schematic of the illustrative pneumaticcircuit 10. Pneumatic circuit 10 includes a first sequence loop 12(approximated as the elements within the broken lines) and a secondsequence loop 14 (outside the broken lines). First sequence loop 12 isinitiated with either a foot switch 16, a remote pushbutton 18, or apanel pushbutton 18A. Foot switch 16 is the illustrated embodiment inthe drawings, however, any of the above foot switch 16, a remotepushbutton 18, or a panel pushbutton 18A, including combinationsthereof, are within the scope of the disclosure.

Sensor 20 (shown in FIG. 16B) senses pressurization and permits passageof pressurized gas through path 22 when foot switch 16, pushbutton 18,or pushbutton 18A is actuated, or any combination thereof. Thepressurized gas shifts the vacuum valve 48 (FIG. 16A), creating vacuumin collection canister 28. Vacuum sensor 30 passes a signal to thevacuum indicator 150 when the vacuum level reaches 20″ Hg vacuum.Pressurized signals from components 30, 22 pass through the “and” gate50 (FIG. 16A) and latch relay 24, which in turn signals cutter cylinder26 to retract to a non-extended position. When cutter cylinder 26 isretracted into the non-extended position, pressurized gas is deliveredto medical device 70, illustratively to operate pneumatic motor 138.However, it should be understood that pressurized gas may be utilizedfor any number of functions in a medical device, and is not restrictedto the illustrative functions shown in hand wand 4.

A saline supply 152 (FIG. 16B) is also illustratively provided tomedical device 70, the saline supply 152 fostering the flow ofbiological material removed by the medical device 70 to collectioncanister 28. Pinch valve 72, which includes pneumatically actuatedstopper 88 (FIG. 16B), controls the flow of saline supply 152 in amanner described further herein.

Collection canister 28 collects biological material from the medicaldevice 70 during the medical procedure using vacuum pressure. Inaddition to the biological material being collected, saline is collectedin this manner. If the vacuum pressure fails, such failure is sensed byvacuum switch 30, and the cycle stops. Otherwise, pressurized gascontinues to be delivered for a period of time determined by timingcircuit 148.

Timing circuit 148 incorporates a restricted orifice that fills volumechamber 144 with gas and eventually signals valve 146 to turn on thepressurized gas to medical device 70. Pressurized gas causes cuttercylinder 26 to advance at a rate controlled by timing circuit 38 untilit reaches the extended position (also the position held duringinsertion of the cannula of the illustrative medical device, describedabove). Such pressurized gas continues to build up in medical device 70until pressure sensor 52 senses a predetermined gas pressure in cuttercylinder 26 and illustratively trips at approximately 24 psi, indicatingthe end of the stroke. At such a point, signaling device 54 causes amomentary audible signal, and also latch relay 24 resets, turning offdevice 70. If signal 22 is still present, the relay 24 will not resetand the process will automatically repeat. If the process repeats theaudible tone has a shorter duration than if it resets.

It is also possible that cutter cylinder 26 does not fully advance tothe extended position before pressure sensor 52 trips. In such aninstance, cutter cylinder 26 may encounter difficulties cutting throughthe mass 142, and pressure will build up in cutter cylinder 26 eventhough the end of the stroke has not been reached. When the cylinderpressure reaches the predetermined amount of 24 psi, sensor 52 trips,regardless of the position of cutter cylinder 26 (and the attachedcutter 134).

Setup switch 44 (FIG. 16B), which is controlled by knob 154 on controlpanel 9 (FIG. 1) allows an operator to load the saline tube into thepinch valve 72 and primes the medical device by actuating, in parallel,the retraction of cutter cylinder 26, the opening of saline pinch valve72, and the opening of vacuum valve 48. During this setup mode, signalsfrom 22 are ignored, thereby inhibiting a cycle start condition.Aspiration switch 40 (FIG. 16B), which is controlled by knob 156 oncontrol panel 9 (FIG. 1) inhibits a cycle start condition and causescylinder 26 to retract, if a signal delivered via path 22 is present thevacuum valve 48 shifts creating vacuum in the canister and the medicaldevice.

Referring to FIGS. 16A-B, pneumatic circuit 10 operates in substantiallythe following fashion. Air compressor 11 is turned on and creates airpressure and flow. The compression process creates heat and condensesthe humidity in the air. At such a point, condensed water is in gaseousstate. The hot moist air is then passed through a fan-driven air-to-airheat exchanger 158 cooling the air and changing the water to a liquidstate. The cooled air is then passed into a coalescing filter 41 wherethe water is captured in the filter media and drips into the bottom ofthe filter bowl. The filtered air then continues out to feed the controlcircuit.

The compressor runs continuously. If pressure is sensed by the reliefregulator of greater than the set point of 70 psi, it will continuouslyvent the excess pressure. If the system is on and not in cycle, 99% ofthe compressor flow rate will vent out of the relief regulator. Whilethe system is cycling the medical device, approximately 40% of thesystem capability will continuously flow through the relief regulator.

The water that is collected in the bottom of the filter bowl isdissipated with water evaporation subassembly 39. Water passes from thefilter 41 through the relief regulator 43 and into the base of thepermeable exhaust member 45. The exhaust member 45 acts as a wick,drawing the fluid up the media. The flow rate through the exhaust member45 and the large “wick” surface area cause the liquid water to evaporateinto a gas state. The flow rate through the enclosure caused by the heatexchanger fans removes the water vapor from the cabinet, thuseliminating the need to collect water and drain it from the system.Illustratively, a filter “muffler” is used as a permeable exhaust member45, the muffler being available from Allied Witan Company, of Cleveland,Ohio, as part number F02.

The pneumatic circuit components are mounted to custom aluminummanifolds 47, 49 minimizing the use of fittings and keeping the systemcompact. The components are “sub-base” style versions of the componentallowing for ease of replacement. Each component that needs adjusted isbench tested and set to the specified level using certified fixtures.Diagrammatic representations of the manifolds can be seen in FIGS.21A-D.

Console 6 is designed to isolate the noise and heat created bycompressor 11 and vacuum pump 19. Design specifications for console 6can be seen in FIGS. 19A-D. Shelf 35 divides the cabinet into twosections. The lower section contains the spring-mounted pumps 11, 19,soundproofing material 37, and fans to isolate vibration, heat, andnoise, as can be seen in FIG. 7.

As shown in various views in FIGS. 22A-B, pinch valve 72 includes aretainer comprised of a central catch 74 and opposing catches 76, 78.See also a view of pinch valve 72 in FIG. 1. Silicone tubing 80 is bentinto a configuration as shown in broken lines, and pushed betweencentral catch 74 and opposing catches 76, 78. When pulled taut, siliconetubing 80 assumes a substantially straight configuration and is disposedunder cantilevered portion 82 of central catch 74, and cantileveredportions 84, 86 of opposing catches 76, 78 respectively, as shown inFIG. 22A. Such a configuration secures the silicone tubing 80 andprevents accidental removal of silicone tubing 80 from pinch valve 72.

Pneumatically actuated stopper 88, shown diagrammatically in FIG. 22B,moves a piston 90 between a stopped position (shown in broken lines) anda flow position. The default position is the stopped position, stoppingthe flow of fluid through the silicone tubing 80.

FIGS. 25A-D show a pair of hose wrap pins that is used to wrap the footswitch tube set and the power cord when the system is not in use. FIGS.26A-B show a foot switch holder. FIG. 27 shows a valve bracket. AndFIGS. 28A-B show an embodiment of tie-down rails.

The test module 92 for testing Airtrol electric pressure switch 120 (asshown in FIGS. 11 and 16A), model number F-4200-60-MM, can be seen inFIGS. 29-33. The switch 120 is placed on test module 92 and clamped inplace, as seen in FIG. 29. A red jumper 94 is connected to the normallyopen (N.O.) terminal 98 of switch 120. Black jumper 96 is connected toCOM terminal 100. A plugged union fitting 102 is connected to an end ofnatural colored tube 104. With an air supply to test module 92 turnedon, 2-position detented button 122 is pulled out and pressure observed.It is further observed when green indicator light 106 turns on. If greenindicator light 106 does not turn on at 20 psi+/−0.5 psi, then button122 should be pushed back in and adjustments made to switch 120, andtesting done again. After the proper target pressure is obtained, agreen dot sticker 108 is placed over the adjustment screw. Pneumaticvacuum switch VP-701-30-MM is tested in a similar fashion, with atargeted setting of 20″ Hg vacuum.

Another test procedure for test module 92 is shown in FIGS. 30 and 31.In such a procedure, Airtrol pneumatic pressure switch 120′ (modelnumber PP-701-30-MM) is tested. Red tube 109 is connected to output port110. Natural tube 104 is connected to input port 112. With an air supplyto test module 92 turned on, button 122 is pulled out and pressure atwhich large green light 114 comes on is observed. If large green light114 does not turn on at 24 psi+/−0.5 psi, then button 122 should bepushed back in and adjustments made to switch 120′, and testing doneagain. After the proper target pressure is obtained, a green dot sticker108 is placed over the adjustment screw.

Yet another test module 92′ for testing various regulators is shown inFIGS. 32 and 33. This test module 92′ is illustratively used for thecutter cylinder regulator 124 (model R4, R01-10 w/60 psi gauge), the airmotor regulator 126 (model R2, R01-12 w/60 psi gauge), and the mainregulator 128 (model R1, R01-12 w/160 psi gauge). The regulators areillustrated schematically in FIGS. 16A-B, and on diagrammatic views ofthe manifolds in FIGS. 20B and 21A-B. During testing, the testedregulator 124, 126, 128 should be set for the appropriate targetpressure (60 psi, 60 psi, and 160 psi, respectively). Next, two O-rings116 (seen in FIG. 32) should be installed in the bottom of the testedregulator. The regulator 124, 126, 128 is then placed on the test module92′ aligning the locating pin and locating hole found on the test moduleand regulator. Regulator 124, 126, 128 is then clamped in place.

Target pressures during testing of regulators 124, 126, 128 variesdepending on the regulator. Model R4 is targeted for 30 psi, rising.Model R2 is targeted for 40 psi, rising. Model R1 is targeted for 60psi, rising. Once pressure is dialed in to the appropriate target, theregulator nut is tightened to prevent knob movement and a permanentmarker is used to mark the cannula position of the regulator gauge.Finally, a green dot is placed in the center of the gauge face.

Illustrative parts used in the production of the above-describedembodiment can be found in FIGS. 34A-C. It should be understood,however, that other parts and constructions are within the scope of thedisclosure.

While the disclosure is susceptible to various modifications andalternative forms, specific exemplary embodiments thereof have beenshown by way of example in the drawings and have herein been describedin detail. It should be understood, however, that there is no intent tolimit the disclosure to the particular forms disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure asdefined by the appended claims.

A plurality of advantages arises from the various features of thepresent disclosure. It will be noted that alternative embodiments ofvarious components of the disclosure may not include all of the featuresdescribed yet still benefit from at least some of the advantages of suchfeatures. Those of ordinary skill in the art may readily devise theirown implementations of a pneumatic circuit that incorporate one or moreof the features of the present disclosure and fall within the spirit andscope of the disclosure.

1. A medical device comprising: a biopsy device comprising a cannulawith an orifice, the cannula being configured for insertion into a bodyto a point such that the orifice is adjacent to a tissue mass to bebiopsied, a cutter housed within the cannula and configured to moverelative to the orifice to selectively cut tissue from the mass, and apneumatic cylinder coupled to the cutter for moving the cutter relativeto the orifice; and a pneumatic circuit coupled to the biopsy device forcontrolling the pneumatic cylinder, the pneumatic circuit comprising asensor configured to sense back pressure in the pneumatic cylinder. 2.The medical device of claim 1, wherein the cannula defines an axis andthe cutter is aligned coaxially with the cannula.
 3. The medical deviceof claim 2, wherein the cutter rotates about the axis.
 4. The medicaldevice of claim 2, further comprising a pneumatic motor controlled bythe pneumatic circuit, the pneumatic motor actuating rotational movementof the cutter.
 5. The medical device of claim 2, wherein the pneumaticcircuit selectively causes the cutter to rotate relative to the cannulaas the cutter approaches and closes the orifice and the pneumaticcircuit further selectively causes the cutter to retract to a retractedposition without rotating.
 6. The medical device of claim 5, wherein thepneumatic circuit provides a signal to the operator when the cutter hascompleted one cycle of moving between the closed-orifice position andthe retracted position and back.
 7. The medical device of claim 2,wherein the pneumatic cylinder causes the cutter to move axiallyrelative to the cannula.
 8. The medical device of claim 1, wherein thepneumatic circuit directs the retraction of the cutter relative to theorifice when a predetermined back pressure is sensed in the pneumaticcylinder.
 9. The medical device of claim 7, wherein the predeterminedback pressure is approximately 24 pounds per square inch.
 10. Themedical device of claim 1, further comprising a pneumatic switchconfigured to permit an operator to selectively operate the cutter byactuating the pneumatic switch.
 11. The medical device of claim 1,wherein the biopsy device is substantially free of magneticallysensitive objects such that it can be operated in conjunction with aMagnetic Resonance Imaging device.
 12. The medical device of claim 1,further comprising a saline supply coupled to the biopsy device, thesaline supply dispensing saline in a manner controlled by the pneumaticcircuit.
 13. The medical device of claim 12, wherein the saline isdirected between the cutter and the cannula.
 14. The medical device ofclaim 12, further comprising a vacuum coupled to the biopsy device forcreating a suction and drawing the saline through the cannula.
 15. Amedical device comprising: a cutter configured to selectively cut tissuefrom a body; a pneumatic cylinder coupled to the cutter for moving thecutter relative to the body; and a pneumatic circuit coupled to thepneumatic cylinder for controlling the pneumatic cylinder, the pneumaticcircuit sensing the back pressure in the pneumatic cylinder andresponsively controlling the pneumatic cylinder.
 16. The medical deviceof claim 15, further comprising a pneumatic motor, wherein the cutterdefines an axis and the pneumatic motor causes the cutter to rotateabout its axis as the cutter is cutting tissue from the body.
 17. Themedical device of claim 15, wherein the pneumatic circuit provides asignal to the operator when the cutter has completed one cycle ofcutting tissue from the body.
 18. The medical device of claim 15,wherein the pneumatic circuit directs the retraction of the cutterrelative to the body when a predetermined back pressure is sensed in thepneumatic cylinder.
 19. The medical device of claim 18, wherein thepredetermined back pressure is approximately 24 pounds per square inch.20. The medical device of claim 15, further comprising a pneumaticswitch coupled to the cutter for selectively operating the cutter. 21.The medical device of claim 20, wherein the pneumatic switch is footpedal operated.
 22. The medical device of claim 20, wherein thepneumatic circuit uses the pneumatic switch as an indication of whetherto initiate another cutting cycle.
 23. The medical device of claim 15,further comprising a saline supply for dispensing saline in a mannercontrolled by the pneumatic circuit.
 24. The medical device of claim 23,wherein the saline is directed to flow around the cutter, providinglubrication to the cutter and providing a flush for tissue cut from thebody by the cutter.
 25. The medical device of claim 15, furthercomprising a vacuum coupled to the biopsy device, the vacuum beingcontrolled by the pneumatic circuit.
 26. The medical device of claim 25,wherein the vacuum is used to facilitate the removal of tissue after thetissue has been cut from the body.
 27. The medical device of claim 15,wherein the tissue is breast tissue.
 28. A method of removing a tissuemass from a body, the method comprising the steps of: inserting a hollowcannula having an aperture into the body such that the aperture ispositioned adjacent to the tissue mass, the hollow cannula housing acutter therein; providing suction to the cannula such that a portion ofthe tissue mass is pulled inside the cannula through the aperture;pneumatically moving the cutter relative to the aperture so that thecutter cuts the portion of tissue mass from the remainder of the tissuemass; and transporting the cut portion of tissue mass through thecannula with the provided suction, wherein the pneumatic movement of thecutter is controlled by a pneumatic circuit comprising a pressuresensor.
 29. The method of claim 28, wherein the step of moving thecutter across the aperture is repeated such that additional portions ofthe tissue mass are removed.
 30. The method of claim 28, wherein thecutter is rotating as it cuts the portion of tissue mass.
 31. The methodof claim 30, wherein the rotation of the cutter is pneumaticallyactuated by a pneumatic motor.
 32. The method of claim 28, wherein themovement of the cutter is pneumatically actuated by a pneumaticcylinder.
 33. The method of claim 28, wherein the pneumatic circuitcontrols the provision of suction and controls the movement of thecutter.
 34. A biopsy device comprising a cannula with an orifice, thecannula being configured for insertion into a body to a point such thatthe orifice is adjacent to a tissue mass to be biopsied; a cutter housedwithin the cannula and configured to move relative to the orifice toselectively cut tissue from the mass; a pneumatic cylinder coupled tothe cutter for moving the cutter relative to the orifice, the pneumaticcylinder being controlled by a controller responsive to back pressure inthe cylinder; and a pneumatic motor coupled to the cutter for rotatingthe cutter relative to the orifice.
 35. The biopsy device of claim 34,wherein the pneumatic motor comprises six pneumatic vanes.
 36. Thebiopsy device of claim 34, wherein the controller is a pneumaticcircuit.
 37. The biopsy device of claim 34, wherein the controllerresponds to a back pressure of approximately 24 pounds per square inch.38. The biopsy device of claim 34, wherein the controller directs thecutter to retract relative to the cannula when a predetermined backpressure is sensed in the pneumatic cylinder.
 39. The biopsy device ofclaim 38, wherein the predetermined back pressure is approximately 24pounds per square inch.